The disclosed embodiments of the present invention relate to power transfer, and more particularly, to a power transfer circuit utilizing power capability proclamation to transfer electrical power from a power source to a charger, and a related power transfer method.
A conventional switching charger utilizes adaptive input current control (AICC) to regulate an input current limit for tracking a maximum power capability of an adaptor, and further utilizes poor adaptor management (PAM) to set input current limit regulation in order to avoid direct current (DC) bus voltage collapse (e.g. undervoltage lockout (UVLO)) and allow a poor adaptor to perform battery charging continuously.
However, power of a wireless power receiver unit (PRU) is limited by power of a wireless power transmitter unit (PTU) and coil efficiency, and collapses easily when provided for a switching charging employing AICC. Specifically, when the wireless PRU supplies power to the switching charging employing AICC, the switching charging tracks a maximum power capability of the wireless PRU, and the wireless PTU collapses easily since no power limit of the wireless PRU is available.
Thus, there is a need for a novel power transfer mechanism to stably supply power to a charger without voltage collapse.